Oregon officials still battling pertussis outbreak that began last spring: vaccination acceleration.(Children's Health)

Physicians in three Oregon counties--Jackson, Klamath, and Lane--continue to battle a pertussis outbreak that surfaced this spring.

As of Aug. 4, 2003, the state of Oregon had seen 272 confirmed cases this year, as defined by the Centers for Disease Control and Prevention, said Hilary Gillette, an epidemiologist with the Oregon State Department of Human Services.

Although the outbreak is spreading to nearby Douglas and Multnomah counties, the highest incidence based on population density remains in Lane, Jackson, and Klamath counties, respectively.

In this outbreak, more confirmed cases occurred in older children, although children younger than 5 …